News Releases Detail

Stabbing on RTD Bus on May 3, 2012

9/21/2012 8:12:21 AM


TO: Detective Tom Wilson, Aurora Police Department

FROM: Brian Sugioka

DATE: 9/19/12


RE:  Stabbing on RTD Bus on May 3, 2012


Dear Tom,


            Your office has requested our office conduct a thorough review of the facts of this incident, to determine if criminal charges are warranted against any of the participants.  For the reasons set forth below, it is my recommendation that no criminal charges be filed against any of the parties involved in this incident.




            The majority of this incident was videotaped by cameras on the bus where the incident happened.  I have thoroughly reviewed the videotape and accompanying audio, and this evidence was critical to the overall decision.  In addition, I have been provided with interviews and written statements of the witnesses to the incident who were on the bus, a video interview of Robert Rodgers, one of the injured parties, as well as a video interview of Michael Walker, the person who inflicted the injuries to Aaron Bishop and Robert Rodgers and caused the death of Bishop.  I have also reviewed the autopsy report.  Finally, I have been given reports from law enforcement describing the physical evidence located at the scene.




Michael Walker, DOB 8/15/59 (age 52).  Five feet eleven inches tall, 145 pounds.   (Criminal history information, or lack thereof, is redacted from this document due to privacy issues) Mr. Walker is employed as a maintenance worker in downtown Denver.  Walker rides this particular bus regularly, and knows the driver and some of the passengers.


Aaron Bishop, DOB 3/26/74 (age 38).  Six feet 1 inch tall, 186 pounds at autopsy.  (Criminal history information, or lack thereof, is redacted from this document due to privacy issues)   He was unemployed on the date of offense, having recently been fired from work as a line cook, due to cursing and threatening other employees and customers.


Robert Rodgers, DOB 3/6/81 (Age 31).  Five feet 9 inches tall, 150 pounds (according to 2011 Nevada ID card information)  (Criminal history information, or lack thereof, is redacted from this document due to privacy issues) Rodgers was employed at the same bar Bishop had recently been fired from.  Rodgers refers to Bishop as his “brother”, although it is unknown if they are actually siblings.




            This summary is drawn from all of the materials I have reviewed.  As mentioned earlier, the videotape itself is the best evidence of the sequence of the altercation.  However, the videotape is limited in that the audio quality is poor at times, and the video only partially captures the end of the altercation which occurred outside of the bus.  The witness statements are particularly useful to fill in some of the dialogue that was not captured by the recording system.  Where there are significant conflicts in the witness statements, that information is noted.


            Aaron Bishop and Robert Rodgers board the RTD bus at 4:23 p.m.  Michael Walker is already on the bus.  Bishop and Rodgers take seats together, facing sideways looking across the middle of the bus.  Walker is in a seat facing forward.  Walker does not appear to pay any particular attention to Bishop and Rodgers at that time, and Bishop and Rodgers do not appear to pay attention to Walker. 


Rodgers had told law enforcement that he and Bishop had been drinking at a bar before getting on the bus, and that Bishop had probably been drinking before meeting up with Rogers.  Toxicology results of Bishop’s blood revealed a BAC of .239.  No test for the presence of drugs or alcohol was conducted on Rodgers and witnesses do not describe indicia of intoxication on Rodgers.  Walker had just left work and had no indicia of intoxication.  Walker was not tested for drugs or alcohol.


            Four minutes after boarding the bus, Bishop and Rodgers open windows on either side of the bus.  This prompts a request from the driver to close the windows.  Bishop and Rodgers do not comply with this request, so the driver stops the bus, walks to the back of the bus, and closes the windows.  Immediately following this action, Walker can be seen saying something to Bishop and Rodgers.  Based on witness statements, this was a statement expressing displeasure at Bishop and Rodgers for opening the windows and delaying the bus.  The audio is not audible, but Walker can be seen turning sideways in his seat and appears to be saying something to Bishop.   Bishop can then be seen standing up and appears to begin to speak to Walker.  Walker responds for a short time, but then turns back around and appears to try to ignore Bishop, putting his earphones in.  Walker then stands up and moves forward on the bus, away from Bishop and Rodgers.  According to Walker, he did so to find another seat but could not.  Walker returns to his own seat after several seconds and puts his earphones back in. 


Approximately two minutes later, a seat is vacated across from and behind Walker.  Bishop immediately takes this seat and begins to glare at Walker, and appears to be saying something to him.  Walker appears to say something back.  The word “fucking” can be heard, but no other detail.  It appears Bishop and Walker are arguing.  After approximately one minute of apparent arguing, Rodgers, who was seated across from Bishop, appears to take exception to something said by Walker, and stands up suddenly and moves aggressively toward Walker.  Rodgers can be heard saying to Walker in a loud tone “don’t fuck with my brother, dude”. Bishop sticks out his arm and restrains Rodgers, who was advancing on Walker.  When Rodgers makes that aggressive movement, Walker, who had been seated, stands up and takes his pocketknife out of his pocket.  Walker uses his other hand to open the pocketknife, behind his back, not in view of Bishop or Rodgers, and then brings the knife down by his side, not brandishing the weapon.  Walker stands still and does not advance on Rodgers or Bishop.


Seven seconds after Walker stood up, Bishop stands up very suddenly and launches himself at Walker, shoving Walker very forcefully with both hands to Walker’s chest.  Walker is shoved backward and almost to the ground, striking a pole with sufficient force to bend the pole.  Rodgers was directly behind Bishop when this occurred, and Rodgers advances on Walker, just behind Bishop. Thus, both Bishop, in the lead, and Rodgers, just behind him, are both advancing rapidly towards Walker, who has been pushed backwards (towards the front of the bus).


As Walker is stumbling backwards after having been shoved by Bishop, he can be seen making a stabbing motion towards Bishop’s chest with his right hand, the one holding the knife.  It appears this is when the first stab wound is inflicted on Bishop.  This is consistent with Walker’s statement that when he was first struck by Bishop he “just started sticking them” with the knife.  As Walker continues to be pushed to the front of the bus by Bishop, just by the front door to the bus, Walker can be seen making another stabbing motion with his right hand, and an object consistent with the pocketknife can be seen in his right hand.  It appears this is when the second stab wound is inflicted on Bishop.


            Walker is shoved a second time, and is backpedaling and stumbling toward the front of the bus.  Walker hits the front windshield with sufficient force to break the windshield and push it out of its frame.  Walker is then shoved out the front door of the bus by Bishop, again with Rodgers directly behind Bishop.  The remainder of the incident is only partially visible on video through the windows of the bus.  Bishop can be seen throwing Walker to the ground on a grassy area just outside the bus.  Rodgers can be heard repeatedly screaming “Aaron!” as Bishop throws Walker to the ground.  At some point during the altercation, Rodgers cannot say when, Rodgers suffers a severe laceration to his hand, and according to his statement was yelling to Aaron to bring attention to Rodgers’ injury.  The entire physical altercation, from the point Bishop shoves Walker on the bus, to the point Bishop can be seen throwing Walker to the ground outside the bus, takes approximately 25 seconds.


            Bishop walks a short distance away from the bus before collapsing in a grassy area a few feet from the bus.  The injuries to Bishop will be covered in the next section, describing the physical evidence.  Rodgers runs to a nearby bar to get assistance for himself and Bishop.


Walker re-enters the bus, still carrying the knife in his right hand, and retrieves his backpack.  According to Walker, he intended to walk home, but passengers on the bus told him he needed to stay and wait for police, which Walker does.  None of the passengers appear to demonstrate any obvious fear of Walker.  Walker can be heard apologizing to the passengers and stating that he was defending himself.


            Witness statements are generally consistent with one another and the video evidence, with several exceptions.  There is agreement that Walker said something to Bishop and Rodgers after the driver had to stop the bus to close the windows.  This statement by Walker is generally described as “if you mess with the driver, you mess with me” or words to that effect.  There is agreement that Bishop and Rodgers invited Walker to get off the bus to fight, and that Walker declined.  However, one witness describes Walker as being the one who invited the others to get off the bus.  There is agreement that after the physical altercation ended, Walker re-entered the bus and apologized.


Witnesses agree that after Bishop changed seats and began to glare at Walker, right before the physical altercation began, Walker told Bishop and Rodgers to leave him alone.  However, the precise recollection of the statement varies from witness to witness.  This statement is described variously as:


”You don’t want this, God’s got me, if you come at me we can handle this”

“You don’t want this, come at me and I will handle you”

“Don’t fuck with me, I’m not your plaything”

“Don’t fuck with me, I‘m gonna hurt you”

“Don’t fuck with me”

“If you come near me, you will pay”


No witness other than Rodgers describes hearing Walker threaten to stab Bishop or Rodgers.




            Walker was briefly interviewed informally at the scene, prior to the formal videotaped interview.  His statements at the scene are consistent with his later videotaped statements, particularly with respect to his belief that he was defending himself.


            Walker was interviewed at the Aurora Police Department at 6:57 p.m. by Detectives Wilson and Sobieski, slightly more than two hours after the incident.  Walker was properly Mirandized, waived his rights, and elected to speak.  At the beginning of the interview, Walker was informed that one of the parties involved in the altercation had died from his wounds.  According to the Detectives, Walker did not know this information previously.  Walker was visibly upset by this, putting his head down and crying for several minutes.  Walker then stated that if he had put his knife down, he might be the one that was deceased.  Walker repeatedly stated he was defending his life.


            After Walker calmed down, Walker described the altercation to the officers.  Walker denies making any verbal or physical threats to Rodgers or Bishop.  Walker states that he told Rodgers and Bishop that he just wanted to get home.  Walker describes Bishop telling Walker that he (Bishop) was getting off at Chambers and Smoky Hill, and Walker interpreted this as an invitation to fight.  This statement can be heard on the bus video.  Walker told Bishop and Rodgers that he was getting off at Buckley.


            Walker described the physical part of the altercation beginning with the first guy (Bishop) hitting him in the face (The video appears to show more of a two-handed shove).  Walker said the second male was right behind the first, as he was being backed down the aisle of the bus.  Walker stated that as he was being backed down the aisle he “just started sticking them”.  Walker describes being struck in the face at least twice, and says both of the other males were bigger than him.  Walker stated that “they was coming at me and I was backing up trying to defend myself.  That’s how that happened”.


            Walker stated that he took the knife out after he felt his life was “at threat”.  He stated “there was two on one in that little space and I just got my knife out”.  It should be noted that the video clearly reveals Walker taking the knife out of his pocket and opening it after Rodgers had made the first aggressive move towards him, but before Bishop shoved him.




Rodgers was interviewed first at the scene.  His initial description of the altercation is generally consistent with the video. In that informal interview, he tells law enforcement that his brother started the altercation.  Rodgers acknowledges inviting Walker to get off the bus with him to finish the argument.  Rodgers states that shortly before Bishop shoved Walker, Walker had threatened to stab Bishop, which according to Rodgers is what triggered Rodgers to stand up suddenly and move towards Walker.  Rodgers concludes the informal interview by stating “I hate to say this, but this was my brother’s fault.”


Rodgers video interview begins with Rodgers acknowledging that he and Bishop had been drinking at a bar earlier that day. Rodgers also believed Bishop had been drinking before meeting up with Rodgers at the bar. 


Rodgers denies opening the windows on the bus.  However, the video clearly shows him and Bishop doing so.


Rodgers reiterates his claim that just before the physical altercation began, Walker had told Bishop “I’ll stab you”.  Rodgers states this is what caused Rodgers to stand up and approach Walker aggressively.  No other witness describes hearing this statement from Walker. 


Rodgers states that when he followed Bishop to the front of the bus while Bishop and Walker were fighting, he was attempting to pull Bishop off of Walker.  This does not appear to be consistent with the video evidence which shows Rodgers right behind Bishop making no effort to restrain Bishop.  It should also be noted that the video shows Rodgers making the first physically aggressive move in what was only a verbal altercation up to that point.




Walker’s pocketknife was of legal size, having a 2.5 inch blade, well under the 3.5 inch limit for concealed weapons.  Walker told police that he habitually carries the knife with him for his work.  No other weapons were recovered from any of the parties and there is no evidence any other weapons were involved.


            Forensic examination of the bus revealed blood drops on the bus consistent in location with the wounds to Bishop being inflicted while he was shoving Walker toward the front of the bus.  Also, a metal pole in the bus, of the type used by passengers to balance themselves when standing, was bent as a result of Walker’s impact with it.  The front windshield had been pushed out of the frame and was lying in the street, as a result of Walker being shoved into it. 




Bishop suffered two stab wounds.  The fatal wound was a narrow, 2.5 inch-deep stab wound that penetrated Bishop’s heart.  The other wound was an approximately 3 inch-deep stab wound to the abdomen, perforating the liver.  Based on the video evidence, it appears Bishop suffered these wounds while still on the bus, and was able to continue assaulting Walker for several seconds after the wounds were inflicted.


Rodgers suffered a severe laceration to his hand, penetrating to the bone.  It is not known at what exact point this wound was inflicted, as Rodgers only noticed the wound after he was separated from Walker.  Rodgers speculated that he may have cut his hand on the windshield frame or could have been cut by Walker’s knife.  It is unknown if Rodgers suffers any long-term disability from the hand injury.


Walker’s wounds consisted of a small contusion on his forehead, and redness, swelling, and pain on his left forearm.  Walker also complained of pain in his hip after the incident, probably caused by being shoved into the pole on the bus, and pain in the left side of his face.




With respect to both Michael Walker and Robert Rodgers, I have considered and rejected a number of potential charges.  It is my ultimate recommendation, for the reasons set forth below, that no charges be filed against either Walker or Rodgers.




The affirmative defense of self-defense played a significant role in this analysis.  For convenience, I will re-state the law concerning self-defense, contained in 18-1-704 C.R.S.:


(1) Except as provided in subsections (2) and (3) of this section, a person is justified in using physical force upon another person in order to defend himself or a third person from what he reasonably believes to be the use or imminent use of unlawful physical force by that other person, and he may use a degree of force which he reasonably believes to be necessary for that purpose.

(2) Deadly physical force may be used only if a person reasonably believes a lesser degree of force is inadequate and:

(a) The actor has reasonable ground to believe, and does believe, that he or another person is in imminent danger of being killed or of receiving great bodily injury; or

(b) The other person is using or reasonably appears about to use physical force against an occupant of a dwelling or business establishment while committing or attempting to commit burglary as defined in sections 18-4-202 to 18-4-204; or

(c) The other person is committing or reasonably appears about to commit kidnapping as defined in section 18-3-301 or 18-3-302, robbery as defined in section 18-4-301 or 18-4-302, sexual assault as set forth in section 18-3-402, or in section 18-3-403 as it existed prior to July 1, 2000, or assault as defined in sections 18-3-202 and 18-3-203.

(3) Notwithstanding the provisions of subsection (1) of this section, a person is not justified in using physical force if:

(a) With intent to cause bodily injury or death to another person, he provokes the use of unlawful physical force by that other person; or

(b) He is the initial aggressor; except that his use of physical force upon another person under the circumstances is justifiable if he withdraws from the encounter and effectively communicates to the other person his intent to do so, but the latter nevertheless continues or threatens the use of unlawful physical force; or

(c) The physical force involved is the product of a combat by agreement not specifically authorized by law.


With respect to Michael Walker, the first charge to be considered is Second Degree Murder, defined as knowingly causing the death of a person.  I did not consider First Degree Murder, as there is clearly insufficient evidence to establish Intent and Deliberation.  With respect to Second Degree Murder, it is doubtful we would be able to establish the element of “knowingly causing the death of a person”.  The knife Walker used was a 2.5 inch pocket-knife.  There were only two wounds to Bishop, and neither of the wounds were inflicted after Bishop was incapacitated or defenseless.  The events occurred extremely quickly and it does not appear the knife strikes were carefully targeted.  Finally, given Walker’s strong emotional reaction to learning of Bishop’s death, it will be difficult to argue that he acted knowingly in an effort to kill Bishop.  Therefore, I do not believe we can establish that Walker knowingly caused the death of Bishop.


Further, with respect to second-degree murder, I believe Walker will be able to establish that he was acting reasonably in self-defense.  I have analyzed self-defense both from the perspective of use of “deadly physical force”, and from use of reasonably proportionate force not amounting to deadly physical force.  Under either test, Walker would be able to establish that he acted in self-defense.   From the perspective of Walker, he was being assaulted by two individuals, both of whom were significantly younger and somewhat bulkier than him.  Walker was in a vulnerable defensive position when he stabbed Bishop, being shoved backwards and pursued by both individuals.  It was reasonable for Walker to use the knife rather than his fists to defend himself, for the same reasons.  He was being assaulted by two individuals and was in a vulnerable position.


“Deadly physical force”, as defined in 18-1-901, is


“force, the intended, natural, and probable consequence of which is to produce death,

 and which does, in fact, produce death.”


As explained previously, the knife involved had a short blade, and only two wounds were inflicted, both in the course of an active assault.  I do not believe death would be the “intended natural and probable consequence” of stabbing someone twice with a pocketknife of this size.  Thus, I do not believe that this case should be analyzed under the “deadly physical force” provisions in the self-defense statute.  That being said, even assuming the force used by Walker meets the definition  of “deadly physical force”,  Walker’s actions would still be justified under that provision.  It would be reasonable for Walker to believe that a lesser degree of force, ie defending himself without a knife, would be insufficient under the circumstances, and it was also reasonable for Walker to believe that he was about to suffer “great bodily injury” as it appeared he was being assaulted by two individuals who were younger and apparently stronger than him. 


            Walker was not the initial aggressor.  There are arguments both ways as to who initiated the verbal argument, but it was clearly Rodgers who made the first physically aggressive move, followed closely by Bishop.  The other exceptions to the self-defense statute are inapplicable.


            I have also considered and rejected Reckless Manslaughter and Criminally Negligent Homicide.  Based on the evidence presented, Mr. Walker’s conduct was not reckless or criminally negligent, but rather were actions taken in self-defense. 


            Walker’s conduct does not meet the elements of Felony Menacing.  Rodgers is the only person who claims Walker made a reference to threatening to stab Bishop.  None of the other witnesses describe Walker making reference to a knife, and no witness describes Walker brandishing the knife prior to using it against Bishop. The video evidence shows Walker opening the knife behind his back, and then keeping the knife down by his side until he uses it.


            I have considered and rejected several other offenses, including Endangering Public Transportation (18-9-115 C.R.S.) Hindering Transportation (18-9-114 C.R.S.), and Harassment (18-9-111 C.R.S.).  For many of the same reasons set forth above, there is no reasonable probability of conviction of any of those offenses. 


            There is no question as to the cause and manner of death in this case.  Clearly, the stab wounds inflicted by Walker caused the death of Bishop.  However, the evidence also establishes that Walker did not knowingly cause the death of Bishop, and was acting reasonably in self-defense.  The People do not have a reasonable probability of disproving self-defense beyond a reasonable doubt at trial.  Thus, no charges are warranted against Walker.




            There is no video evidence showing Rodgers striking Walker.  In his interview, Walker describes being struck by both Bishop and Rodgers, but it appears from the video that Rodgers was directly behind Bishop during the altercation on the bus and was not in a position to strike blows.  It is possible Rodgers may have struck Walker after they got off the bus, during the part of the incident not covered by video, but there is no evidence of this other than Walker’s statement.  There is simply not enough evidence to support assault charges against Rodgers.  Thus, no assault charges are warranted against Rodgers.


I have considered and rejected a number of other offenses and theories, including Endangering Public Transportation, Harassment, and complicitor liability for the actions of Bishop.  Rodgers conduct does not meet the elements of Hindering or Endangering Public Transportation.  Given that Rodgers was behind Bishop during the fight and there is insufficient evidence to show Rodgers actively participated in the fight, we cannot establish that Rodger’s actions Endangered or Hindered Public Transportation.  Based on the video and audio evidence and witness statements I do not believe the elements of those charges can be established based on the evidence available at this time.    




            The Aurora Police Department conducted a thorough investigation of this tragic incident.  Based on the results of that thorough investigation, it does not appear charges are warranted against any of the participants in the altercation that resulted in the death of Aaron Bishop. 





                                                                                                Brian Sugioka

                                                                                                Senior Deputy District Attorney